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CF app JVM trigger GC

CF app JVM trigger GC causes the GC to be triggered for a Java based Cloud Foundry app's JVM.

CF App JVM Trigger GC

Use cases

CF app JVM trigger GC:

  • Evaluates how the application handles unexpected performance drops during GC pauses.
  • Measures the impact of increased GC activity on application latency.
  • Tests the application's behavior in scenarios where memory is not being freed as expected.
  • Simulates high memory pressure and assess the application's stability and performance under such conditions.
  • Ensures the application can recover gracefully from GC-induced disruptions and maintain functionality.

Mandatory tunables

TunableDescriptionNotes
organizationOrganization where the target app resides.For example, dev-org.
spaceSpace where the target app resides.The space must reside within the given organization. For example, dev-space.
appThe app in which chaos will be injected.The app must reside within the given organization and space. For example, cf-app.
deploymentModel The deployment model used for setting up the fault injector. It supports model-1 and model-2. Model-1 assumes that the fault-injector exists within a diego cell VM whereas Model-2 assumes that the fault-injector exists within a jumpbox VM. Supports model-1 and model-2. For more information, go to Deployment Model.

Optional tunables

TunableDescriptionNotes
javaHome Value of the JAVA_HOME environment variable. Not required if the Java binary file path is added to the Linux PATH env or JAVA_HOME env is added to the Linux PATH env.
instanceAffectedPercentage Percentage of total number of app instances that will be targeted. Default: 0 (1 instance). For more information, go to instance affected percentage.
faultInjectorPort Local server port used by the fault-injector utility. Default: 50320. If the default port is unavailable, a random port in the range of 50320-51320 is selected. For more information, go to fault injector port.
duration Duration through which chaos is injected into the target resource (in seconds). Default: 30s. For more information, go to chaos duration.
skipSSLValidation Skip SSL validation while invoking CF APIs. Supports true and false. Default: false. For more information, go to skip SSL validation.
rampTime Period to wait before and after injecting chaos (in seconds). Defaults to 0.
boshDeployment The bosh deployment under which the CF components are managed. It can be obtained using the BOSH CLI command bosh deployments. For more information, go to BOSH deployment.
faultInjectorLocation Location of the fault injector with respect to the Cloud Foundry VMs. Supports local and vSphere. For more information, go to Fault Injector Location.

CF secrets

The following Cloud Foundry secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/cf.env file in the following format:

CF_API_ENDPOINT=XXXXXXXXXXXXXXXXXXX
CF_USERNAME=XXXXXXXXXXXXXXXXXXXXXXX
CF_PASSWORD=XXXXXXXXXXXXXXXXXXXXXXX
UAA_SERVER_ENDPOINT=XXXXXXXXXXXXXXX
BOSH_CLIENT=XXXXXXXXXXXXXXXXXXXXXXX
BOSH_CLIENT_SECRET=XXXXXXXXXXXXXXXX
BOSH_CA_CERT=XXXXXXXXXXXXXXXXXXXXXX
BOSH_ENVIRONMENT=XXXXXXXXXXXXXXXXXX
info

If the secrets file is not provided, the secrets are attempted to be derived from environment variables and the config file by the fault-injector.

ENV nameDescriptionExample
CF_API_ENDPOINTAPI endpoint for the CF setuphttps://api.system.cf-setup.com
CF_USERNAMEUsername for the CF userusername
CF_PASSWORDPassword for the CF userpassword
UAA_SERVER_ENDPOINTAPI endpoint for the UAA server for the CF setuphttps://uaa.system.cf-setup.com
BOSH_CLIENTUsed by the bosh CLI, the BOSH clientadmin
BOSH_CLIENT_SECRETUsed by the bosh CLI, the BOSH client secretUBu9Fu3oW35sO6fw12auPH76gsRTy7
BOSH_CA_CERTUsed by the bosh CLI, the file path for BOSH CA certificate/root/root_ca_certificate
BOSH_ENVIRONMENTUsed by the bosh CLI, the BOSH environmentbosh.corp.local

Fault injector ENVs and config file

If /etc/linux-chaos-infrastructure/cf.env file is not provided, fault-injector attempts to derive the secrets from environment variables or a configuration file. Any secret that is re-declared will be overridden in the following order of decreasing precedence:

  1. /etc/linux-chaos-infrastructure/cf.env file
  2. Environment variables
  3. Configuration file

The configuration file should be provided at /etc/linux-chaos-infrastructure/cf-fault-injector.yaml:

cf-api-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
username: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
password: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
uaa-server-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client-secret: XXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-ca-cert: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-environment: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

A mapping between all the three formats for providing the secrets is as follows:

cf.envENVcf-fault-injector.yaml
CF_API_ENDPOINTCF_API_ENDPOINTcf-api-endpoint
CF_USERNAMEUSERNAMEusername
CF_PASSWORDPASSWORDpassword
UAA_SERVER_ENDPOINTUAA_SERVER_ENDPOINTuaa-server-endpoint
BOSH_CLIENTBOSH_CLIENTbosh-client
BOSH_CLIENT_SECRETBOSH_CLIENT_SECRETbosh-client-secret
BOSH_CA_CERTBOSH_CA_CERTbosh-ca-cert
BOSH_ENVIRONMENTBOSH_ENVIRONMENTbosh-environment

vSphere secrets

These secrets are provided only if vSphere is used as the deployment platform for CF.

The following vSphere secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/vsphere.env file in the following format:

GOVC_URL=XXXXXXXXXXXXXXXXXXXXXX
GOVC_USERNAME=XXXXXXXXXXXXXXXXX
GOVC_PASSWORD=XXXXXXXXXXXXXXXXX
GOVC_INSECURE=XXXXXXXXXXXXXXXXX
VM_NAME=XXXXXXXXXXXXXXXXXXXXXXX
VM_USERNAME=XXXXXXXXXXXXXXXXXXX
VM_PASSWORD=XXXXXXXXXXXXXXXXXXX
ENV Name Description Notes
GOVC_URL Endpoint for vSphere For example, 192.168.214.244
GOVC_USERNAME Username for the vSphere user For example, username
GOVC_PASSWORD Password for the vSphere user For example, password
GOVC_INSECURE Skip SSL validation for govc commands For example, true
VM_NAME Name of the vSphere VM where the fault-injector utility is installed For example, cf-vm
VM_USERNAME Username for the VM guest user For example, root
VM_PASSWORD Password for the VM guest user For example, password

BOSH deployment

The boshDeployment input determines the BOSH deployment name under which all the CF resources are managed. You can obtain it using the BOSH CLI command bosh deployments.

The following YAML snippet illustrates the use of this input:

# bosh deployment
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
name: cf-app-jvm-trigger-gc
labels:
name: app-jvm-trigger-gc
spec:
cfAppJVMChaos/inputs:
duration: 30s
faultInjectorLocation: vSphere
app: cf-app
organization: dev-org
space: dev-space
boshDeployment: cf

Instance affected percentage

The instanceAffectedPercentage input specifies the percentage of total number of app instances that will be targeted. It defaults to 0 (1 instance).

The following YAML snippet illustrates the use of this input:

# instance affected percentage
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
name: cf-app-jvm-trigger-gc
labels:
name: app-jvm-trigger-gc
spec:
cfAppJVMChaos/inputs:
duration: 30s
faultInjectorLocation: vSphere
app: cf-app
organization: dev-org
space: dev-space
boshDeployment: cf
instanceAffectedPercentage: 50

Fault injector location

The faultInjectorLocation input determines the location of the fault injector with respect to the infrastructure. It is the location where the fault-injector utility is executed.

  • It can be local, that is, the same environment used by the infrastructure, or a remote machine.

The following YAML snippet illustrates the use of this input:

# cf deployment platform
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
name: cf-app-jvm-trigger-gc
labels:
name: app-jvm-trigger-gc
spec:
cfAppJVMChaos/inputs:
duration: 30s
faultInjectorLocation: vSphere
app: cf-app
organization: dev-org
space: dev-space

Skip SSL validation

The skipSSLValidation input variable determines whether to skip SSL validation for calling the CF APIs.

The following YAML snippet illustrates the use of this input:

# skip ssl validation for cf
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
name: cf-app-jvm-trigger-gc
labels:
name: app-jvm-trigger-gc
spec:
cfAppJVMChaos/inputs:
duration: 30s
faultInjectorLocation: vSphere
app: cf-app
organization: dev-org
space: dev-space
skipSSLValidation: true

Fault injector port

The faultInjectorPort input determines the port used for the fault-injector local server.

The following YAML snippet illustrates the use of this input:

# fault injector port
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
name: cf-app-jvm-trigger-gc
labels:
name: app-jvm-trigger-gc
spec:
cfAppJVMChaos/inputs:
duration: 30s
faultInjectorLocation: local
app: cf-app
organization: dev-org
space: dev-space
faultInjectorPort: 50331